Airway epithelium repair after infection consists of wound repair, re-synthesis of the extracellular matrix (ECM), and tight junction proteins. In humans, EPs
7630 obtained from
roots reduces the ...severity and duration of acute respiratory tract infections. The effect of EPs
7630 on tissue repair of rhinovirus-16 (RV-16) infected and control human airway epithelial cells was assessed for: (i) epithelial cell proliferation by manual cell counts, (ii) epithelial wound repair by "scratch assay", (iii) ECM composition by Western-blotting and cell-based ELISA, and (iv) epithelial tight junction proteins by Western-blotting. EPs
7630 stimulated cell proliferation through cAMP, CREB, and p38 MAPK. EPs
7630 significantly improved wound repair. Pro-inflammatory collagen type-I expression was reduced by EPs
7630, while fibronectin was increased. Virus-binding tight junction proteins desmoglein2, desmocollin2, ZO-1, claudin1, and claudin4 were downregulated by EPs
7630. The RV16-induced shift of the ECM towards the pro-inflammatory type was prevented by EPs
7630. Most of the effects of EPs
7630 on tissue repair and regeneration were sensitive to inhibition of cAMP-induced signaling. The data suggest that EPs
7630-dependent modification of epithelial cell metabolism and function might underlie the faster recovery time from viral infections, as reported by others in clinical studies.
Bacterial extracellular polymeric substances (EPS) have been recently found to contribute most for metal removal in nanoenhanced bioremediation. However, the mechanism by which NPs affect EPS-metal ...interactions is not fully known. Here,
sp. was employed to explore the role of EPS after in vivo exposure to Cd/Pb and polyvinylpyrrolidone (PVP) coated iron oxide nanoparticles (IONPs, 20 mg L
) for 72 h. Cd-IONPs produced the highest concentrations of EPS proteins (136.3 mg L
), while Cd induced the most production of polysaccharides (241.0 mg L
). IONPs increased protein/polysaccharides ratio from 0.2 (Cd) to 1.2 (Cd-IONPs). The increased protein favors the formation of protein coronas on IONPs surface, which would promote Cd adsorption during NP-metal-EPS interaction. FTIR analysis indicated that the coexistence of Cd and IONPs interacted with proteins more strongly than with polysaccharides. Glycosyl monomer analyses suggested mannose and glucose as target sugars for EPS complexation with metals, and IONPs reduced metal-induced changes in monosaccharide profiles. Protein secondary structures changed in all treatments, but we could not distinguish stresses induced by metals from those by IONPs. These findings provide greater understanding of the role of EPS in NP-metal-EPS interaction, providing a better underpinning knowledge for the application of NP-enhanced bioremediation.
In October 2018, the order
Bunyavirales
was amended by inclusion of the family
Arenaviridae
, abolishment of three families, creation of three new families, 19 new genera, and 14 new species, and ...renaming of three genera and 22 species. This article presents the updated taxonomy of the order
Bunyavirales
as now accepted by the International Committee on Taxonomy of Viruses (ICTV).
The potential effects of extracellular polymeric substances (EPS) on the behavior and toxicity of silver nanoparticle (Ag-NPs) and silver sulfide nanoparticle (Ag2S-NPs) remains ambiguous. The ...interaction of EPS from Bacillus subtilis with Ag2S-NPs, metallic Ag-NPs, or ionic Ag, and the associated plant safety had been examined in this study. The biological impacts of Ag-NPs and Ag2S-NPs were Ag form-dependent and highly influenced by microbial EPS. Compared with metallic Ag-NPs, Ag2S-NPs exert inert biological impacts, as revealed by 3.44 times lower Ag bioaccumulation in wheat (Triticum aestivum L.) seedlings and nearly reduce plant biomass when wheat was subjected to 1.0 mg-Ag L−1 of Ag-NPs and Ag2S-NPs with the transfer factors of 151.56–930.87 vs. 12.52–131.81, respectively. These observations were coincident with the low dissolved Ag (Agdiss) in the Ag2S-NPs treatment than the Ag-NPs treatment (114.0 vs. 0.0791, μg L−1). Compared with the enhanced toxicity of Ag2S-NPs to wheat, Bacillus subtilis EPS significantly alleviate the phytotoxicity of Ag-NPs, as revealed by the relative root elongation (7.15–45.40% decrease vs. 2.39–11.75% increase), and malondialdehyde (1.47–83.22% increase vs. 8.57–25.25% decrease) and H2O2 (11.27–71.78% increase vs. 5.16–36.67% decrease) contents. These constrasting plant responses of B. subtilis EPS are mainly caused by their complexation property with toxic Ag+ and nutrient elements for wheat stressed by Ag-NPs and Ag2S-NPs, respectively. Our findings highlight the importance of rhizospheric EPS in affecting the biogeochemistry and ecotoxicity of metal nanoparticles including Ag-NPs and Ag2S-NPs in agricultural systems.
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•EPS reduce the uptake of Ag in media with AgNO3, AgNPs and Ag2S-NPs.•EPS alleviate the toxicity of AgNO3 and AgNPs, but enhance the toxicity of Ag2S-NPs.•EPS affect the bioaccumulation and phytotoxicity of metal nanoparticles.•Rhizospheric EPS is critical in affecting health safety of metal nanoparticles via food chains.
The role of marine plastic debris and microplastics as a carrier of hazardous chemicals in the marine environment is an emerging issue. This study investigated expanded polystyrene (EPS, commonly ...known as styrofoam) debris, which is a common marine debris item worldwide, and its additive chemical, hexabromocyclododecane (HBCD). To obtain a better understanding of chemical dispersion via EPS pollution in the marine environment, intensive monitoring of HBCD levels in EPS debris and microplastics was conducted in South Korea, where EPS is the predominant marine debris originate mainly from fishing and aquaculture buoys. At the same time, EPS debris were collected from 12 other countries in the Asia-Pacific region, and HBCD concentrations were measured. HBCD was detected extensively in EPS buoy debris and EPS microplastics stranded along the Korean coasts, which might be related to the detection of a quantity of HBCD in non-flame-retardant EPS bead (raw material). The wide detection of the flame retardant in sea-floating buoys, and the recycling of high-HBCD-containing EPS waste inside large buoys highlight the need for proper guidelines for the production and use of EPS raw materials, and the recycling of EPS waste. HBCD was also abundantly detected in EPS debris collected from the Asia-Pacific coastal region, indicating that HBCD contamination via EPS debris is a common environmental issue worldwide. Suspected tsunami debris from Alaskan beaches indicated that EPS debris has the potential for long-range transport in the ocean, accompanying the movement of hazardous chemicals. The results of this study indicate that EPS debris can be a source of HBCD in marine environments and marine food web.
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•A brominated flame retardant, HBCD, was assessed in EPS debris and microplastics.•HBCD was widely detected in EPS debris from the Asia-Pacific coastal region.•Additive HBCD are dispersed via EPS pollution in marine environments.•EPS debris can be a source of HBCD in the marine environment.
A brominated flame retardant, hexaboromocycledodecane, was widely detected in EPS marine debris and microplastics from the Asia-Pacific coastal region.
•Nonylphenol exposure enhances the algal extracellualr polymeric substances excretion.•The polysaccharides and proteins are specifically overproduced in response to nonylphenol.•The enhanced ...extracellualr polymeric substances decrease the NP cellular internalization.•Extracellualr polymeric substances enhance algal tolerance to nonylphenol.
Dictyosphaerium sp. is tolerant to nonylphenol (NP); however, knowledge regarding the mechanisms involved in NP tolerance is limited. In this study, a batch of algal culture experiments were carried out to elucidate the underlying mechanisms by investigating the production and composition of extracellular polymeric substances (EPS) in algae exposed to NP. The excretion of EPS was significantly enhanced (P < 0.001) in algae exposed to 4 and 8 mg/L of NP. The polysaccharides in soluble EPS and the proteins in bound EPS were specifically overproduced. The three-dimensional excitation and emission matrix fluorescence spectra analyses indicated that tyrosine- and tryptophan-like substances were the main functional compositions in the proteins of EPS. In addition, enhanced EPS secretion significantly alleviated the toxicity of NP to the algae by the reduction of cell internalization, as indicated by the higher IC50, biomass, and cell growth rate in the algae with EPS. These discoveries along with the characterizations by algal cell surface hydrophobicity analysis, scanning electron microscopy, and Fourier transform infrared spectra spectroscopy demonstrated the vital role of EPS in the algal resistance to NP.
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•A higher flux was achieved in the GAC/GDM system compared to GDM control.•A higher DOC removal (high- and low-MW) was achieved in the GAC/GDM system.•GAC functioned as a pre-filter ...and reduced foulants accumulated in biofouling layer.•GAC improved the eukaryotic diversity and functioned as a eukaryotic pre-incubator.
An integrated gravity-driven membrane (GDM) and granular activated carbon (GAC) filtration process was operated for 193days to investigate the influence of integrated GAC on the flux stabilization, permeate quality, composition of the biofouling layer and eukaryotic community compared with a GDM control system. The results revealed that the presence of GAC resulted in a strongly increased stable flux (6Lm−2h−1, compared to 2Lm−2h−1 in the GDM control). Furthermore, the GAC/GDM system exhibited a significant removal of dissolved organic compounds (DOC) (50–70%) due to the adsorption and biodegradation process. By contrast, the DOC in the permeate of the control was approximately 20–30% higher than in the raw water, which was attributed to the hydrolysis of high-MW compounds. Furthermore, the composition of the biofouling layer attached on the membrane surface was significantly influenced by the presence of GAC, leading to a reduction of accumulated organic compounds by 60%. Likewise, the extracellular polymeric substances (EPS) were obviously reduced in the GAC/GDM system, especially the tightly bound EPS in the biofilm and EPS deposited in membrane pores. Additionally, the GAC could function asa eukaryotic pre-incubator, resulting in a higher diversity of the eukaryotic community and improving predation in the biofouling layer. Furthermore, a more porous, heterogeneous and permeable biofouling layer was observed in GAC/GDM. The higher flux in GAC/GDM system was attributed to (i) lower organic foulants (especially EPS) accumulated in the biofouling layer and membrane pores and (ii) highly heterogeneous structures due to improved activity of eukaryotes in the biofouling layer. These results are essential to develop robust maintenance-free, cost-effective and energy-efficient drinking water treatments.
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•FNA pre-exposure overcame the limitations of in-sewer CaO2 dosing.•Joint use of FNA and CaO2 increased sulfide and methane control by 267% and 390%•Various reactive nitrogen/oxygen ...species destabilized the dense biofilm structure.•A notable increment of 40.05% in COD in sewer effluent with CaO2-based strategy.•Novel in-sewer CaO2-based strategy has multifaceted downstream benefits.
Although biocides have proven highly efficient in controlling hazardous emissions and mitigating organic carbon loss in sewers, the resistance of biofilm and extracellular polymeric substances (EPS) to biocides has emerged as a significant impediment to addressing these challenges. In this study, a promising strategy of calcium peroxide (CaO2) dosing assisted by free nitrous acid (FNA) pre-exposure overcame these limitations. Prior to a 6-hour exposure to 0.1 % (w/v) CaO2, a 2-hour pre-exposure to a low dose of 0.26 mg-N/L FNA demonstrated a significant enhancement in sulfide and methane control efficiency by 267.14 % and 390.47 %, respectively, compared to direct exposure to 0.2 % CaO2 for 12 h. Moreover, there was a notable increase of 40.05 % in soluble COD level in the effluent. FT-IR and XPS analyses discovered the disruption, migration, and dissolution of biofilm, accompanied by a substantial increase in membrane permeability (up to 2.89 folds). Additional analysis revealed that the synergistic effects of various reactive nitrogen/oxygen species destabilized the structure of EPS, e.g., declining total EPS yield, disintegrating humic acid-like and tryptophan- and protein-like substances, reducing hydrogen bond in β-sheet of proteins. Further down-regulation of node genes associated with sulfidogenesis and methanogenesis verified the toxic mechanism at the genetic level. Microbial community analysis revealed a significant reduction in the abundance of sulfate-reducing bacteria and methanogenic archaea, leading to an extended recovery period for sulfide and methane production in sewer biofilm. This study provides an effective strategy and in-depth mechanisms for biofilm control, applicable beyond sewer biofilm.
•Sludge dewaterability was improved by Fe(II)-PMS with high CST and SRF reduction.•Optimal conditions were identified: PMS 0.9mmol/gVSS, Fe(II) 0.81mmol/gVSS, pH 6.8.•The protein in EPS conducted a ...detrimental influence on sludge dewaterability.•The release of EPS-bound water induced the enhanced sludge dewatering.
The effect of Fe(II)-activated peroxymonosulfate (Fe(II)-PMS) oxidation on the waste activated sludge (WAS) dewatering and its mechanisms were investigated in this study. The capillary suction time (CST), specific resistance to filterability (SRF) of sludge and water content (WC) of dewatered sludge cake were chosen as the main parameters to evaluate the sludge dewaterability. Experimental results showed that Fe(II)-PMS effectively disintegrated sludge and improved sludge dewaterability. High CST and SRF reduction (90% and 97%) was achieved at the optimal conditions of PMS (HSO5-) 0.9mmol/gVSS, Fe(II) 0.81mmol/gVSS, and pH 6.8. Extracellular polymeric substances (EPS) and three-dimensional excitation–emission matrix (3D-EEM) fluorescence spectroscopy before and after Fe(II)-PMS oxidation were determined to explain the enhanced dewatering mechanism. The release of EPS-bound water induced by the destruction of EPS was the primary reason for the improvement of sludge dewaterability during Fe(II)-PMS oxidation.
Nanoplastics are widespread in the environment, and their increased persistence is an indisputable and severe threat. The impacts of these nanoplastic particles on the soil system and terrestrial ...plant growth, as well as how the EPS secreted by soil microbes would influence their toxic effects remain largely unexplored. This study focuses on the toxic effects of polystyrene nanoplastics (PSNPs) of various surface charges (plain, aminated, and carboxylated) and concentrations (12.5, 25, and 50 mg/l) in Allium cepa and illustrates the effects of eco-corona formation in reducing the toxic impact. The endpoints evaluated included cytotoxicity, oxidative stress (total ROS, superoxide, hydroxyl radical generation and lipid peroxidation), and antioxidant enzyme activity (catalase and guaiacol peroxidase). Among the various surface charges, aminated PSNPs showed the highest toxicity for all the three concentrations tested. The results showed a concentration reliant increase in the levels of cell death, oxidative stress generation, and antioxidant enzyme activity for pristine PSNPs irrespective of their surface charges. Upon aging in the EPS medium a decrease in the toxic effects was noted for all the indicators. This could be a result of the agglomeration due to eco corona formation over the PSNPs in the EPS medium. The TEM images and MHD analysis for both pristine and the coronated PSNPs confirmed the agglomeration.
•Cell physiology of onion roots treated with Polystyrene nanoplastics studied.•Eco-corona formation by soil EPS over the polystyrene nanoplastics.•Coronated Polystyrene nanoplastics tend to agglomerate reducing their cell uptake.•Reduced oxidative stress and toxic effects by coronated Polystyrene nanoplastics.
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